Process for the manufacture of artificial-stone plates.



L. LUKACS.

PROCESS FOR THE MANUFACTURE OF ARTIFICIAL STONE PLATES.

APPLICATION FILED OCT. 17, 1908.

Patented Jan. 2, 1917.

ill

- INVENTOK:

WITNESSES:

LUDWIG LUKACS, OF BUDAPEST, AUSTRIA-HUN GARY.

PROCESS FOR THE MANUFACTURE OF ARTIFICIAL-STONE PLATES.

Specification of Letters Patent.

Application filed October 17, 1908. Serial No. 458,145.

To all whom it may concern:

Be it known that I, Luowrc LUKACS, a

subject of the King of Hungary,'residing at Budapest, Austria-Hungary,have in.- vented c'ertain new and useful Improvements in Processes forthe Manufacture of Artificial-Stone Plates, of which the following is aspecification.

This invention relates to the manufacture of artificial stone plates,and 'aims to provide certain improvements therein.

It has heretofore been proposed to manufacture artificial stone platesfrom ground fibrous material anda hydraulic binding means. One suchprocess is described in English Patent No. 3970 of 1906, and consists ingrinding asbestos or some other fibrous material and adding water untilthe same is in a pulpy condition. a A cement or the like is also reducedto pulpy condition, and i the fibrous material and cement are placed inseparate receptacles, from WlllCh they are transferred to an endlessbelt by means of rotating drums or the like in such manner thatalternate layers are built up in any desired numbers. According to thisprocess the number of receptacles is invariably an uneven one, theobject being to form the two outer layers of cement. Under thesecircumstances the first, third and fifth receptacles contain the cement,while the second and fourth contain the asbestos or other fibrousmaterial. The minimum number of receptacles which are required is three,which number is usually adopted.

The present process dispenses with the use of more than two receptacles;one of such receptacles is adapted to contain the cement washed up inwater, and the other the asbestos mixed with water. Preferably theprocess is practisedin such a way that. the two outer cement layers areapplied to the molding cylinder (usually employed) by themselves, thatis, without a layer of asbestos. This result is obtained in a simplemanner by arranging the rotating drums or the like in the receptacles sothat they can be disconnected.

According to the present process it is advantageous to work with lesswater than has heretofore been necessary, and to change the weightproportions of the cement and asbestos. Good results are obtained forinstance by using 10-20 kilos of asbestos'to 150-200 kilos of Portlandcement, mixing such cement with 200 to 300 liters of water.

The asbestos is also mixed with approximately the same quantity ofwater.=

The preferred mode of practising the process is as follows: The cementand asbestos' or other material which has been mixed with water in theabove mentioned proport1ons, are placed in proper receptacles, each ofwhich is provided with one or more agitators, and with a drum orscreening cylinder covered with felt or the like. The agitators are thenoperated, and after a suflicient mixing the drum or screening cylinderPatented Jan. 2, 1917.

arranged-in the cement receptacle and the molding roll are started. Thedrum of the asbestos receptacle is however disconnected, so that theendless belt does not receive any asbestos. The belt therefore transmitsto the molding roll only cement, in which connection it may be statedthat the cement layer can be transferred to the molding roll in anydesired thickness. When the cement layer has reached the desiredthickness, the drum of the asbestos receptacle is then con .nected, sothat the endless belt which is now receiving cement from the firstreceptacle, also receives asbestos from the drum of the secondreceptacle, and both of these layers are accordingly transferred to themoldingcylinder by the belt. After a suitable number of cement andasbestos layers have been applied to the cylinder, the asbestosreceptacle is again disconnected, so that a layer of cement only istransferred to the molding cylinder. This exterior layer of cement maybe of any desired thickness. The plate taken off from the moldingcylinder may be pressed, worked and finished in any well known manner.If colored plates are required, a coloring matter may be added to theasbestos or the cement.

The improved process described has the advantage that it requiressmaller mechanism than the processes heretofore practised, that theformation of the layers of the product takes place with great certainty,that the consumption of water is decreased, and that the impermeabilityand solidity of the finished product can be increased as the two outerlayers of cement can be formed of any desired thickness. The process canfor example be carried out with the apparatus schematically shown in thedrawing herewith, in which,

Figure 1 is a front view. Fig. 2 a section of the apparatus employed.

The properly spread cement paste will be the asbestos deposited withwater in the vessel II. Both vessels are provided with agi tator la anddrums w. The drum of the cement vessel is preferably overlaid with felt,while the asbestos vessel is provided with the sieve drum. The strippingof the drum of the asbestos vessel happens in this 'Way,the arm h whichcarries the weight 8 is fastened by pin 6 to the frame 9 whereby theendless band 6 does not come into contact with the drum w of theasbestos vessel (in the drawing the vessel II) so that the endless bandI) takes up no asbestos. If now the pin 6' is withdrawn the arm It fallsdown, the roller 03 consequently presses by means of the weight 8 theendless band b on to the drum :1; (in the drawing the vessel I), so thatfrom the vessel cement or asbestos as the case may be is applied to theendless band. The receiver or forming roll which receives the ocment orasbestos layer is shown at a.

\Nhile I have described in detail one form of the invention, I do notwish to be limited thereto, as variations may be made therein withoutdeparting from the invention.

IV hat I claim is A process of manufacturing artificial stone composedof layers of asbestos and cement, the outside layers being of cement,consisting in delivering onto an endless belt, at an initial stage, asingle layer of cement, transsigned my name in the presence of two subscribing witnesses.

. LUDWIG LUKACS. Witnesses:

ST. JAMES INTAIN,

MICHAEL ALBINOS.

